Re: Date Trivia Question

On Fri, 08 Jan 1999 15:01:51 GMT, HowardParks_at_my-dejanews.com wrote:

>In article <36954d7d.109434177_at_news.erols.com>,
> cathexis_at_erols.com wrote:
>> Greetings ng,
>> The date datatype is supposed to be valid from 1/1/4712 B.C.
>> until 12/31/4712 A.D. Does antbody know why this particular range was
>> chosen? Just curious.
>>
>> Cathexis_at_erols.com
>>
>
>That starting day is the starting day for the Julian calendar. A friend sent
>the follow to me, I don't know the source, looks like an encyclopedia entry.
>
>Julian Date
>
>The number of days since noon on January 1, -4712, i.e., January 1, 4713 BC
>(Seidelmann 1992). It was proposed by J. J. Scaliger in 1583, so the name for
>this system derived from Julius Scaliger, not Julius Caesar. Scaliger
>defined Day One was as a day when three calendrical cycles converged. The
>first cycle was the 28 year period over which the Julian calendar repeats
>days of the week (the so-called Solar Number). After 28 years, all the dates
>fall on the same days of the week, so one need only buy 28 calendars. (Note
>that since the Gregorian calendar was adopted the calendar now takes 400
>years to repeat.) The second was the 19 year Golden Number cycle over which
>phases of the moon almost land on the same dates of the year. The third cycle
>was the 15 year ancient Roman tax cycle (the so-called Indiction). Scaliger
>picked January 1, 4712 BC on the Julian Calendar as Day One. The three cycles
>coincide every 7980 years (Tøndering).
>
>Howard Parks
>1 Peter 4:10
>
>-----------== Posted via Deja News, The Discussion Network ==----------
>http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own

        Thanks alot to everybody who responded. To judge from responses; Day One relates to the Julian Date, Day_Last is the date Oracle 8i will come out <grin>.

        As a corrolary to Day_Last; this will also be the date when Varchar will be assigned an identity unique from Varchar2<grin,grin>. Thanks all. Any other responses, feel free. Received on Fri Jan 08 1999 - 21:34:48 CST